The Internet Engineering Task Force (IETF) RFC 4904 defines a standard Session Initiation Protocol (SIP) protocol mechanism to transport gateway trunk information between gateways to direct routing at a receiving gateway. RFC 4904 describes this mechanism as mainly a “TDM origination—VoIP—TDM termination perspective”. In RFC 4904, for example, the tgrp tag is only a physical TDM trunk designation to a carrier and the rn-context is only generically described as a “scope” of where the trunk-group information is valid or understood.
The leading number of each reference number within the drawings indicates the figure in which that reference number is introduced and/or detailed. As such, a detailed discussion of reference number 101 would be found and/or introduced in FIG. 1. Reference number 201 is introduced in FIG. 2, etc.